Named Records#

About#

• Field Names make records self-documenting
• Can mix positional and named fields
• Type inference works with named fields
• Better readability than positional records

Main Topics#

1. Basic Syntax

   • Definition: Colon-separated name-value pairs
   • Example:

     var user = (name: 'Alice', age: 30);
     

2. Type Annotations

   • Definition: Explicit named record types
   • Example:

     ({String name, int age}) getUser() {
       return (name: 'Bob', age: 25);
     }
     

3. Accessing Fields

   • Definition: Dot notation access
   • Example:

     var person = getUser();
     print(person.name); // 'Bob'
     print(person.age);  // 25
     

How to Use#

• API Design: Return clearly named data
• Configuration: Group related settings
• Data Transfer: Between function calls

How It Works#

1. Type Safety: Field names are part of type
2. Memory: Same efficiency as positional
3. Patterns: Work with all pattern features

Example:

({double lat, double lng}) getLocation() {
  return (lat: 47.6062, lng: -122.3321);
}

void main() {
  var location = getLocation();
  print('Latitude: ${location.lat}');
}

Conclusion#

Named records bring clarity to data grouping by labeling fields while maintaining all the performance benefits of positional records. They’re particularly valuable when field meanings aren’t obvious from position alone.